Cultural, religious homogeneity is only possible in some societies right now; those which have not yet completely developed the cosmopolitan mass-urbanization and globalization such as has been adopted in the west.
The only chance for these societies is to adopt an alternative system of economic and social development in the next few decades, but that does not seem too possible.
For the west, the only way any sort of homogeneity of this nature could occur is by de-urbanization and de-globalization, and so a switch to agrarianism and localization of community. In order for this to be done, the west needs to go through a heavy shift in trajectory, in fact, a reversal. The only way this will happen on a mass scale is through disaster.
The thing is, I’m beginning to lean towards the idea that as things start getting worse here, religious, traditionalist people will be forced to form communities of their own. Rob Dreher conceived of something known as the “Benedict Option” whereby localized communities of religious traditionalists are formed, and if we take modern liberal society to its modern conclusion (the mass moral and social decay will inevitably lead to an unsustainable society), then one can conclude that these communities which are self-sustaining (the family is the base economic unit of society, and those societies which preserve the family model will survive), will grow while mainstream society declines, until a point comes where the traditional model of community becomes desirable and standard. From this, monarchical forms of government can easily form.
So, truly I do think that there is some measure of possibility for society to “correct” itself, but in the end, God’s Will be done. I’m a long-term optimist, and a short-term pessimist. Problem is, it’s much easier to predict things short-term, so stay tuned for the next few decades.